Determination of serum proteins in 600 healthy adults by high resolution electrophoresis revealed a higher incidence of monoclonal bands than previously reported. This finding shifted the emphasis of characterizing these bands in the serum of normal subjects form begin tranmsient to that of undetermined significance requireing fuarther evaluation. Subsequently, studies in patients with lymphoma and myeloma revealed the presence of weak monoclonal bands in these patients not detectable by other electrophoretic methods. Identification electrophoresis with immunofixation electroporesis.